Preparation of activated carbon from kenaf by activation with H3PO4. Kinetic study of the dsorption/electroadsorption using a system of supports designed in 3D, for environmental applications

Abstract

Activated carbons were prepared from kenaf by chemical activation with phosphoric acid in different concentrations. Its electrical conductivity was also determined. From the series of prepared activated carbons, those with better textural properties, chemistry and high electrical conductivity were elected for their use in adsorption and electroadsorption processes. The removal of Cu (II) ions from aqueous media is of great interest due to their harmful effects on health and environment. The aim of this work was to study the kinetics in the process of retention of copper ions in aqueous solution by adsorption and electroadsorption using activated carbon. Thus, when comparing both processes it was observed that the adsorption equilibrium times were generally greater than those corresponding to electroadsorption. Different kinetic models were applied. The kinetic models applied to the adsorption/electroadsorption processes indicated that the pseudo-second order model described both processes in a better way than the pseudo-first order model. The values of R2 in electroadsorption kinetics were closer to 1 than those obtained in adsorption kinetics. Therefore, it can be affirmed that the pseudo-second order model for the samples, object of study, is better adjusted to the electroadsorption process.